#include<stdio.h> 
#include<math.h>
int main()
{
	for(int year=2020;year<=2050;year++)
	{
		if(year%4==0)
		{
				printf("%d是闰年\n",year);
				continue;
		}
		if(year&400==0)
		{
			if(year%100==0)
			{
				printf("%d是闰年\n",year);
				continue;
			}
		}
		printf("%d不是闰年\n",year);
	}
	return 0;
}

